Healthy, cheap, quick, cold ideas (for a growing teen) PACKED LUNCH?

I get all the wholemeal bread and fillings, I've got my sandwich bit and fruit bit pretty much covered. It's alternatives to crisps, sweets and chocolate I'm after. I'm thinking: dry cereal as opposed to crisps, yoghurt, I like raisons but not fussed on cheese, apricots, nuts or seeds in general. Any snackish ideas? Proteinfull, I'm a-growing!